1. Field of Invention
This invention relates to the field of golf clubs. More specifically, it relates to an improved club head with a swing-weight housing and variable swing-weights for metal wood and wood wood clubs.
2. Description of Prior Art
Many improvements have been made over the years in the design of golf clubs with the desire to improve one's game and to increase a players competitive advantage. A recent development is that of the metal wood and oversized metal wood, Metal woods began an equipment revolution in the late 1970's embracing a simple concept of perimeter weighting designed, simply put, to make the game easier. Traditionally, woods (clubs usually used for tee shots and longer fairway shots) have had heads made of hard woods such as persimmon or laminated maple. Wood is softer than metal and therefore provides a softer feel at impact. Better players appreciate this because it gives than a feeling that they can work with the ball--deliberately curving the ball to the left or right--because the ball stays on the club face a split second longer. However, the tendency of wood to warp or split, coupled with the increasing cost of material and labor, has led to the development of metal heads for woods. Such metal woods typically comprise a hollow cast metal shell filled with a synthetic plastic foam material.
The metal wood has achieved a large measure of success in terms of acceptance in use by skilled golfers. nevertheless, many golfers still prefer traditional "wooden" woods, because of what they consider to be a non-optimal weight distribution in metal wood heads. Specifically, a very important element of the club head design is the concentration of as much mass of the head as possible into the face of the club in the portion of the head behind the face. (This process is called foreweighting, done to bring the center of gravity forward in the club head, promoting a lower shot trajectory.--Reference,"Clubsmarts", buying golf clubs that work, Author Jonathan Abrahams.) This puts the mass of the head where it effectively contributes to energy imparted to the ball, rather than being merely "dead weight" that limits the velocity of the club head when it is swung. In other words, such a distribution of the mass in the club head increases the total mass. Maximizing the effective mass results in a little or no loss in the achievable club head velocity. The result is a greater shot distance, since the energy imparted to the ball by the club is proportional to the effective mass of the club head times the square of the club head velocity.--Generally this is true, unless the face construction is so rigid and inflexible that some energy is lost because the face deflects less and the ball deforms. (Reference, Golf Magazine, August 1998, page 70).
Preferably the mass in the club head is distributed around the perimeter of the club face. Perimeter weighting gives the club a larger sweet spot. Thus, the perimeter weighted club is more forgiving. That is, a golfer need not strike the ball in the center of the club face to project the ball in a straight path. The enlarged sweet spot of a perimeter weighted club face allows the golfer a larger margin of error when striking the ball. A hit off center still achieves a straight shot.
Recently, metal woods have become larger and oversized metal woods are not very popular. It is desirable to maximize the size of the oversize club head without increasing the weight of the club head to achieve maximum distance and velocity. In producing a larger oversized metal club head, therefore, the walls of the club head are thinner than a normal size club to avoid increasing the weight of the larger club and reducing the swing velocity. With their thinner walls, the oversized metal woods are more susceptible to failure by cracking or crushing, due to the lack of an internal supporting structure. The present invention corrects this.
Normal size and fairway metal woods have a thicker wall section than the oversized metal woods. A thicker wall section increases the club head weight, reducing club head speed, or, swing velocity. Conversely, a thinner wall or lighter weighted club head would increase the club head speed, or swing velocity. The best of both worlds is a desirable feature. Having a much heavier club head while maintaining or increasing club head speed or swing velocity translates into a greater shot distance over the norm, since the energy imparted to the ball by the club is proportional to the effective mass of the club head times the square of the club head velocity.--A feature not available in the present day golf clubs, for the oversized, normal or fairway clubs The present invention corrects this problem.
Counterbalancing is the process of reducing the club's swingweight by adding weight to the grip end. Total weight increases and swingweight decreases. In producing today's golf clubs, no thought has been given to an automatic counterbalancing effect. This problem has been corrected by this invention.
Swingweight refers to the distribution of weight in a golf club. Weight is deposited in the head end and in the grip end of the golf club and the relationship of those weights is the club's swingweight. It has nothing to do with the overall weight. Two clubs may have the same overall weight, but if one of them has a greater ratio of weight in the head, it will feel heavier, and thus have a heavier swingweight. Beginning golfers, women, juniors and seniors prefer swingweights with very little weight in the head (more in the grip) so they feel lightest and it makes it easier to create club head speed. No thought has been given to the present day golf clubs to have a variable swingweight. This problem has been solved and corrected by this invention.
The top of the metal club head in some oversized club heads is so thin that a golfer may crush or crack the metal club head by stepping on the crown. It is also subject to failure by allowing the crown to strike the sole of another club when inserting it into the golf bag. The present invention corrects this problem.
Another disadvantage of the conventional metal wood club heads is that they are molded or cast with an opening in the bottom or sole portion of the club head. A sole plate is welded over the opening to seal the club head. The sole plate weld seam creates a structural discontinuity at the juncture of the front edge of the sole plate and bottom edge of the face plate. This structural discontinuity or weld seam may be subject to failure as the face strikes the ball or the sole strikes the ground. The present invention corrects this problem.
On a practical level, wooden clubheads provide playability that, generally, woods of other materials can't match. However, a disadvantage of the wood wood clubs is that they have the majority of the weight behind the sweet spot with the added lead weights.
This means a mis-hit shot doesn't have that weight to help it along, as it does with the peripherally weighted metal wood golf clubs. The result is a substantial drop-off in performance for shots hit off the sweet spot. For that reason, standard-sized wooden heads will do little for the golfer who fights inconsistency. The present invention corrects this problem.
Golf clubs are designed with varying degrees of loft, which range from a minimum of about 8 degrees for a number 1 wood to a maximum of a bout 29 degrees. The different degrees of loft help to control the trajectory and distance a golf ball is hit. The lower lofted clubs are used for hitting a ball long distances, with the least amount of trajectory. The higher lofted clubs are preferred for hitting the ball shorter distances with a higher trajectory. The problem with the existing clubs is that it is often difficult to obtain adequate lift in the lower lofted clubs, while in the higher lofted clubs, offshoot is a problem. These problems are corrected by this invention.
Invention, U.S. Pat. No. 5,362,055, an oversized metal wood, violates all the principles of perimeter weighting and club face thickness flexibility. The club in this patent has an insert cavity formed by support walls to accept an insert made of cycolac or an ABS resin. The insert is attached to the insert cavity with an adhesive or epoxy and a plurality of metal pins securing the insert in its cavity. The insert cavity supporting walls project rearward and perpendicular to the plane of the club face wall and forming a "U" shaped beam. The interior surface of the club face is reinforced with three ribs. This combination of insert cavity ("U" shaped beam), the epoxy, the insert and plurality of metal pins, makes for a thick and rigid face. With a rigid or stiff club face there is loss of energy during the time the ball is on the club face, and the ball deforms more. If the face was less rigid or stiff and so constructed that it would deflect a little more, the ball would deform less. The result would be a smaller loss of energy at impact and the ball would stay on the face longer, resulting in a higher launch angle and lower spin rate. This would also mean a longer carrying distance. (Reference: Golf Magazine, August 1998, page 70). Also, as you go beyond the "center" of the sweet spot to the insert cavity supporting walls, the club face becomes even more rigid. The total thickness of the club face at that point equals the thickness of the wall which the insert rests upon, plus the depth of the insert cavity supporting wall with the club face thickness, forming a "Z" section structure. This makes for an extremely rigid structural member and little club face deflection upon impact with the golf ball. At that point the ball would deform more at impact, with a loss of energy during the time the ball is on the club face. The "sweetspot" is "limited to the insert", but is defeated by its rigidity.
There has been a concern in the above patent that the primary faults of the other club heads is the thinness at the crown portion, which subsequently crumble at impact. The above patent welds a thin crown to a thin crown plate and relies upon the seam weld to strengthen the crown. The crown could be further strengthened if it had a little bit more thickness-to it. A good portion of this additional weight could be applied if the club face were redesigned to a less rigid one, and less weighty one. Eliminating the insert cavity supporting walls, insert, epoxy and the plurality of metal pins, the weight savings could be utilized for a thicker crown and thicker crown plate, and/or for various other design features. (Reference: U.S. Pat. No. 5,489,094 shows such a way to eliminate most parts, and to provide a greater sweetspot) Also, unless there are other features that could be incorporated in the club head internal cavity, the cavity opening can only be limited to the crown, face or sole portions of the club head. The above invention only provides the crown opening to cast the club head internal cavity and some ribs with no other reinforcing structure other than relying on the crown welds for strength. The present invention, although utilizing a crown opening, has a different function, purpose and result than the above invention in addition to correcting the problems and faults listed. The present invention utilizes the crown opening as the only means to add the supporting club head structure and other design features.
A metal wood and wood wood golf club with a swing-weight housing, variable swing-weights, a counterbalancing effect, and a variable (ratio) swingweight constitutes the present invention correcting the shortcomings of the traditional club heads. Metal wood club heads are hollow, cast in a variety of metal alloys, to which a hollow metal shaft is attached. The metal wood comprises an upper metal surface (the crown), a front ball striking surface (the face) which extends from the heel to the toe of the club head a lower metal surface or sole portion comprised of three distinct surfaces or contours: (1) the front portion of the sole which extends from the lower edge of the face backwards along the sole of the convex portion of the sole, (2) the rear portion of the sole which extends forward from the rear junction of the sole and crown to its junction with the convex portion of the sole, and (3) a convex surface located between the front and rear portions of the sole surface.
The hosel is located on the crown near the heel end of the club head and penetrates the crown portion as a hollow metal cylinder. The golf club shaft (a hollow shaft) is attached to the club head by penetrating through a circular opening in the center of the hosel, to a fixed depth called the "stop". Above the "stop", and centrally located between the "stop" and inner surface of the crown is an opening of sufficient diameter to permit entry of a synthetic plastic foam material. The hosel, as a hollow metal cylinder, extends from the "stop" to the uppermost surface of the "swing-weight housing". The "swing-weight housing" is a self contained housing as a cavity within the club head cavity. It has a vertical and horizontal member or plate attached to each other and forms an obtuse angle. The vertical and horizontal members are bounded and formed to the hosel (heel), toe, inner surface of the sole and inner surface of the face. This structural member serves as a reinforcement for the sole plate, face and as a beam between the heel and toe of the club head. This structural member is not available in the standard conventional club heads which can deform on impact. The horizontal member has an opening to facilitate the casting process. Upon completion of the casting process, a plate equal to the thickness of the horizontal member is welded (or brazed) to close the opening. The only and logical place to cast the "swing-weight housing" is through the crown opening since the heel, face, toe and sole are formed with it. Now, the only access to the "swing-weight housing" is through the opening in the hollow metal shaft located at the grip end. The opening is secured by a nylon plug and seal. By removing the nylon plug, we may add the swing-weights" equal to the volume of the "swing-weight housing". Once added the "swing-weights" travel on a downward path through the shaft, into the hosel extension and into the "swing-weight housing". Replacing the nylon plug and seal secures and restricts the "swing-weights" to a travel only between the grip end of the shaft and the "swing-weight housing" in the club head. Thus, on address, the "swing-weights" are in the club head. On the upswing, the "swing-weights" travel from the club head, through the hosel extension, up the hollow shaft, coming to rest in the grip end of the shaft. On the down swing the process is reversed until the combined weight of the club head and "swing-weights" make contact with the ball. The "swing-weights" are in the grip end of the hollow shaft at the start of the downswing. Thus, the club head feels lighter making it easier to create club head speed. This feature is non-existant in the traditional and conventional clubs. (Thus, we have a "Variable Swing-weight".) The "variable swing-weights" consist of any free flowing material such as small metal balls, shot, metal filings, granules and pellets. The "swing-weights" material is made of any metal or metal alloy with a specific gravity range of 0.87 to 21.37. The "swing-weights" may also consist of dry sand or any non-toxic or acidic liquids such as free flowing oils and water with a specific gravity of 0.82 and upward. The "swing-weight" material is not limited to the above, any small free flowing material can be used.
The interior surface of the club face wall is reinforced and formed with vertical ribs. The ribs reinforce the front face allowing it to be thin and flexible, yet having the structural strength of a thicker surface. The thickness of the face wall shall have a spring-like action so as to have a trampoline effect. A loss of energy occurs whenever two objects collide. During the microseconds that a ball is on the club face, some energy is lost because the face deflects and the ball deforms. The face then, should be constructed that would deflect a little more so the ball would deform less. Further more, the ball would stay on the face microseconds longer, resulting in a higher launch angle and lower spin rate, meaning a longer carry distance. (Reference: Golf Magazine, August 1998, page 70.) This is an additional advantage to the present invention which offers a greater trajectory and distance over the traditional and conventional clubs as a result of its "swing-weight housing" and "variable swing-weights". This is in contrast to invention U.S. Pat. No. 5,362,055 which has a complex face structure consisting of "U" and "Z" beams. These beams and insert with a plurality of screws adds extra weight and rigidity to the club face contributing to the loss of energy when striking the ball. Also, the metal and weight saved by the present invention in eliminating that complex structure, is best utilized in part, in the crown area in which their major concern was a thin crown. The balance of the metal and weight saved would be utilized in the casting of the "swing-weight housing". Any additional metal required for the "swing-weight housing" could be taken from the areas requiring less metal due to its reinforcing beam structure.
The invention is further characterized by a crown opening and crown plate which is welded to it. Since the internal cavity of the club head cannot be cast without an opening, the only logical place for it would be in the crown, as, (1) it is impossible to cast the "swing-weight housing" with its cavity opening any other place because it is formed with the heel, face, toe and sole of the club head. (2) the crown opening provides an access for the welding of a plate to secure the "swing-weight housing" cavity. (3) the crown opening provides access when welding the separate vertical and horizontal plates to the heel, face, toe and sole which forms another embodiment of the "swing-weight housing". and, (4) the structural members of the "swing-weight housing" make up a beam which reinforces the heel, face toe and sole of the club head, and adds additional weight to the sole plate. The crown opening shall be kept to a minimum within practical limits to minimize the crown seam which is formed when welding the crown plate to the crown opening.
U.S. Pat. No. 5,362,055 calls for an opening at the crown having a lip or angle formed at its edge so that the crown plate fits into the opening and engages the lip or angle of the opening to support the crown plate. The lip or angle is excess metal, which could best be utilized in the crown wall thickness or as part of the present invention in the swing-weight housing.
The present invention provides better utilization of the metal used. The present invention eliminates the lip or angle in the crown opening. By forming a few small tabs on the top of the crown plate, just slightly overlapping the crown, and inserting the crown plate in the crown opening, the top surfaces of the crown plate and crown are aligned. During the welding operation these tabs could be burned off, or ground off just prior to the welding operation of each locating tab. A further smoothing or grinding operation of the weld is still required in any case. With this process precious metal is saved and utilized in the other areas as needed. Another option is to use a fixture holding the crown plate while welding to the crown.
The crown is effectively divided into three smaller sections by the crown plate seam and is therefore stronger and less flexible than a similar crown without a seam. A thicker and reinforced crown with a seam is less susceptible to crushing. Moreover we have a strengthened crown with the additional thickness from the metal and weight saved from the overly rigid club face of the invention U.S. Pat. No. 5,362,055. The balance of the weight savings may be utilized in the beam structure of the "swing-weight housing". The club head of the present invention is thus stronger than a club of equal weight, volume and material.
The preferred embodiment of the club head shell is formed of a 6AL4V titanium alloy, containing 6% aluminum, 4% vanadium, and 90% titanium, making the impact surface significantly stronger than elemental titanium. Titanium is 34-45% lighter than steel and a 17-4 stainless steel head weighing 206 grams would weigh less than 125 grams if made of titanium. Although the preferred embodiment of the club head shell is 6AL4V titanium alloy, any structurally sound metal alloy may be used such as titanium-aluminum alloy, preferably 92% aluminum and 8% titanium with some variation of the alloy composition, a 17-4 stainless steel with maraging face, a 15-5 stainless steel or even a body of pure titanium with a face of 90T-6AL-4V.
A swingweight (ratio) is defined as the distribution of weight in a golf club. Two clubs may have the same weight, but if one of them has a greater ratio of weight in the head, it will feel heavier, thus having a heavier swingweight. Conversely when there is more weight in the grip end, it makes the club feel lighter, making it easier to create club head speed. With the addition of a swing-weight housing and the variable swing-weights we now have a variable swingweight. On the address position of the club, the swing-weights are in the club head. On the upswing, the swing-weights travel from the swing-weight housing in the club head to the hosel extension and into the hollow shaft, coming to rest at the nylon plug assembly at the grip end of the hollow shaft. Now the club head is lighter. On the downswing the process is reversed where the swing-weights travel from the grip end of the hollow shaft, coming to rest in the club head. Thus, a "Variable Swingweight". The transition of the swing-weights from the club head to the grip end of the hollow shaft provides another advantage--an "Automatic Counterbalancing" effect.
Counterbalancing is the process of reducing the club heads swingweight (ratio) by adding weight to the grip end. The transfer of the swing-weights from the club head to the grip end of the clubhead on the upswing accomplishes this, creating club head speed on the downswing. Thus an "Automatic Counterbalancing" effect.
In the present day or traditional club heads, the process of obtaining adequate lift with the lower lofted clubs and offshoot in the higher lofted clubs is corrected by the swing-weights and the swing-weight housing with a greater trajectory and distance.
Normal size drivers and fairway/utility metal woods have a thicker wall section than the oversized metal woods. This is attributed to their reduced volume and in some cases a heavier weight than the oversized club head. For the normal size drivers and fairway/utility club heads we can reduce the wall thickness in each club head for use in the casting of the swing-weight housing. Additionally, we can further reduce the wall thickness in each club head, to the wall thickness used in the oversized driver. By reducing the wall thickness still further the total weight of the swing-weight housing cast in the cavity of the club head and the club head is less than the weight of a standard driver and fairway/utility club head in each case. Now, we have a set of club heads that are lighter than the standard or conventional club heads. This reduction in weight increases club head speed with an additional trajectory and shot distance when the ball is hit, since the energy imparted to the ball is proportional to the effective mass of the club head (club head plus swing-weights on the downswing) times the square of club head velocity. With the oversized club head we only had a slight increase in club head speed due to the momentum created by the swing-weights on the down swing of the club head, plus the extra weight of the swing-weights, With the normal size drivers and fairway/utility clubs heads we have the additional speed created by a lighter club head, plus the weights of the swing-weights themselves. In using anyone of the variable swing-weights we have also changed the CG of the club head, in each of the various CG's created by various swing-weight housing configurations. Swing-weight housing also reinforces the club head.
In each of the preferred and other embodiments we have created a swing-weight housing located in the cavity of the club head. Although the swing-weight housings take on a specific configuration in each of the drawings, it is not to be construed that it may not take another configuration. By altering the heights (from the sole to the crown), and widths (from the face to the convex portion) and the shape of the swing-weight housing and its proximity to its intended function, in conjunction with the variable swing-weights, we can produce a swing-weight housing for greater backweighting, foreweighting, heel-toe weighting, and sole weighting, to mention a few, but not limited to those mentioned. In each of these swing-weight housings we have now changed the vertical and horizontal CG of the club head creating a plurality of swing-weight housings. With each change of swing-weights from a selection of the variable swing-weights we now have a plurality of CG's changing the CG's of the plurality of swing-weight housings. With each CG change of the swing-weight housings and each CG change of the variable swing-weights we may now incorporate each with the various lofted club heads.
The disadvantage of today's wood wood clubs is that they have the majority of the weight behind the sweet spot, meaning a mis-hit shot doesn't have the weight to help it along as with the peripherally weighted metal wood golf clubs. The result is a substantial drop-off in performance for shots hit off the sweet spot. For that reason standard sized wood wood heads will do little for the golfer fighting inconsistency. The present invention corrects this problem by applying the principles of the metal wood golf club to the wood wood club. By machining or carving a "swing-weight housing" and tunnel leading to the hollow shaft, and adding the "variable swing-weights" and nylon plug assembly, we have accomplished all of the principles listed in this invention.-With one exception, unless treated , we should not use any free flowing oils or water as "swing-weights". An option for the laminated woods is that the swing-weight housing cavity can be precut in each lamination prior to applying the adhesive.
Accordingly, besides the objects and advantages of my golf clubs with a "variable swingweight", "variable swing-weights", and "swing-weight housing" described in my invention, several objects and advantages of the present invention are:
(A) Solution of a long-felt and unsolved need:--This invention provides a greater trajectory and shot distance over the normal or traditional golf clubs. Normally, golfers try to increase their swing velocity by compensating for their fixed club head weight, and thus golf ball distance. By doing so, the forced swing invariably throws the golfer off balance, creating a "hook" or "slice" rather than a line drive. The heavier the club head the less swing velocity, and conversely, the lighter the club head the easier it is to create club head speed. With the present invention the golfer need only to have a normal swing for a greater shot distance and trajectory due to its unique "swing-weight housing" and "variable swing-weights".
(B) New principle of operation:--This invention utilizes a new principle of operation with its unique "variable swingweight", "swing-weight housing", "variable swing-weights" and feature of a "counterbalancing" effect. The object is to make the club head heavier with the same or, slightly greater swing velocity providing a greater trajectory and shot distance. (The energy imparted to the ball by the club is proportional to the effective mass of the club head times the square of the club head velocity.) This is accomplished by this invention utilizing its "swing-weight housing" and "variable swing-weights" previously described in detail.
(C) Unsuggested combination:--The prior art references do not contain any suggestion (expressed or implied) that the present invention may be combined.
(D) Novelty:--The invention is different from all previously know arts or counterparts, due to its "variable swingweight", "variable swing-weights", "swing-weight housing" and counterbalance effect, previously described, creating longer ball drives and trajectory with the same club head speed and increased club head weight.
(E) Durability:--The golf club will last longer due to its internal structural configuration. The "swing-weight housing" is a structural member formed with the heel, toe, face and sole of the club head, a feature not available in present day golf club heads.
(F) Unexpected results:--The results achieved by the invention are new, unexpected, superior, mismatched, unsuggested, unusual, and surprising. With a "variable swingweight", "varied swing-weights", "swing-weight housing" and a "counterbalancing" effect a golfer can expect a higher trajectory and an increased shot distance proportional to the SpGr of swing-weight used. A golfer can remove the "nylon plug and seal" securing the "swing-weights" restricted to a movement between the grip end of the shaft and "swing-weight housing", remove the original "swing-weights", and replace them with either a higher or lower SpGr "swing-weight" from a range of 0.82 to 21.37. The "swing-weight" change affects the golf balls trajectory and shot distance to a greater or lesser degree. This is accomplished using the same swing velocity and combined weight of club head plus the "variable swing-weights", since the energy imparted to the ball is the mass times the square of the velocity.
(G) Speed:--There is a slight increase in the club head speed due to the momentum of the "swing-weights" during the downward swing, which would provide a slight increase in trajectory and shot distance over the conventional or traditional clubs.
(H) Ease of use:--The invention is used as any other traditional or conventional golf clubs.
(J) Lack of implementation:--If the invention were in fact obvious, because of its many advantages, such as a "variable swingweight" (ratio), "variable swing-weights", a "swing-weight housing" which increases the structural integrity of the club head, a counterbalancing effect of the "swing-weights" since the "swing-weights" are in the grip end of the club at the start of the downswing, and the ability to have a heavier club head without affecting the swing velocity providing for a higher trajectory and shot distance, those skilled in the art surely would have implemented it by this time. That is, the fact that those skilled in the art have not implemented the invention despite its many and great advantages, indicates that it is not obvious.
The above and other features of the invention, including various novel details of construction and combination of parts, will be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular devices embodying the invention are shown by way of illustration only and not as limitations of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the claims.